An on-duty New York City police officer was killed on Wednesday after a man walked up to her police vehicle and began to fire shots through the window, authorities said.

Officer Miosotis Familia, a 12-year veteran assigned to the New York Police Department's 46th Precinct's Anti-Crime unit, was taken to a Bronx area hospital where she later died, according to the NYPD. She was 48-years-old.

The department said the officer was struck in the head in an "unprovoked attack" while sitting in a marked police command van - which had been parked in the area since March because of increased gang activity.

The NYPD said the suspect was shot and killed by responding officers and that there were "no outstanding suspects."

An innocent bystander was also shot and hospitalized with non-life threatening injuries, according to the police department. The officer's partner, who was also in the vehicle, was not injured in the attack, the department said.

The suspect, identified as 34-year-old Alexander Bonds of New York City, pulled a gun on the responding officers and led them on a block-long foot chase before he was killed, police said, noting that a silver revolver was recovered at the scene.

New York City Mayor Bill de Blasio's press secretary said the mayor had been briefed on the matter and attended the hospital.

"It is clear this was an unprovoked attack on police officers who were assigned to keep the people of this great city safe," New York City Police Commissioner James O'Neill said in a press conference early Wednesday at Saint Barnabas Hospital, where the officer was transported. "She was sitting in the vehicle and he came up and fired a round into the vehicle. I don't know if anything else could be more unprovoked than that."

He noted that the area where the shooting took place had been troubled by gun activity.

Patrick Lynch, president of the NYC Patrolmen's Benevolent Association, said people in the area should be on the look out for anti-police activity.

"This kind of violence against police officers can not stand. We need the public's help," Lynch said while speaking at Wednesday's press conference. When you someone that's making threats [or] doing something against police officers, you need to let us know. You need to be our eyes and ears."